dv=chr(val(substr(valid_pw,17,4))/asc(staf_name))+chr(val(substr(valid_pw,5,4))/asc(staf_name))
mv=chr(val(substr(valid_pw,9,4))/asc(staf_name))+chr(val(substr(valid_pw,21,4))/asc(staf_name))
yv=chr(val(left(valid_pw,4))/asc(staf_name))+chr(val(substr(valid_pw,13,4))/asc(staf_name))
pwv=dv+mv+yv
dwv=ctod('&dv/&mv/&yv')+90
